Two-phase fogging jet nozzle

Abstract

The invention relates to a device for generating a two-phase fluid jet, the device comprising a rotary nozzle. The device comprises: • a fixed base (10) having: • a central connector (14) for connecting an inlet of a first phase, opening out at the centre of the inner surface of the fixed base; • a peripheral connector (13) for connecting an inlet of a second phase, opening out at the periphery, in an annular region, of the inner surface of the fixed base; • a fixed body (20) which is secured to the base and comprises: • a central channel (34) for passage of the first phase; • surrounded by a coaxial annular chamber (46) for passage of the second phase; • a body (30) which is rotatable about an axis corresponding to the longitudinal axis (21) of the fixed body and which has at least one rotating seam arranged in the interface with the fixed body; • the rotary body (30) having a connector for receiving a two-phase diffusion nozzle (40) having a longitudinal axis (41) which is not aligned with the longitudinal axis (21) with the fixed body (20); • a central channel (100) for supplying the nozzle with the first phase, the port opening out at the upstream face of the body via an opening that opens out in the central channel; • and at least one peripheral channel (102) which communicates with the coaxial annular chamber for passage of the second phase; • the body comprising a means for being driven in rotation with respect to the fixed body.

Description

Two-phase fog jet nozzle

[0001] The present invention relates to the field of producing and propelling a two-phase mixture of at least one gas and one liquid, in particular for extinguishing a fire, cooling equipment, or forming a mist. The mixing takes place in a nozzle where the interaction of a high-speed stream of gas with a water jet atomizes water droplets in the water jet to form a mist of very small or minute droplets, thereby forming a two-phase mixture of water mist droplets entrained and transported by the gas stream. When the relative flow rate between the two fluids is high, the inertial forces that are exerted result in the formation of bubbles or droplets.

[0002] Such two-phase mixtures have remarkable cooling performance and limit damage caused by water and fumes by causing low and localized wetting, the absence of any nuisance in the surrounding area. These mixtures are produced either by fixed installations placed for example on the ceiling of an industrial, tertiary or residential building, a tunnel, the fuselage of an aircraft or a ship, or in the passenger compartment / cabin of an aircraft pilot or an industrial equipment operator, or in installations located on industrial sites or in forest areas, or by portable equipment in the form of fire hoses operated by a firefighter or by an autonomous motorized vehicle.

[0003] The finer the mist, the higher the droplet speed, and the higher the droplet kinetic energy, the greater their ability to penetrate deep into the fire. As the heat exchange surface increases, cooling and inerting are even greater. High-pressure water mist also blocks radiant heat. For example, the temperature can remain bearable just a few meters from a fire heated to 800°C, and it attenuates shock waves caused by an explosion, for example.

[0004] The gas supplying the nozzle can be an inert gas, such as nitrogen, carbon dioxide, argon, or simply air, or even oxygen. State of the art

[0005] PCT patent application WO2022 / 090662 describes a prior invention by the same inventor. It describes a fire hose fed by a two-phase supply pipe, comprising a nozzle, which can optionally be extended by a variable geometry ejection nozzle, with a multifunction control handle and possibly peripheral elements to form, for example, portable equipment. The system comprises a convergent-divergent mixing chamber opening directly into a deformable nozzle connected in a sealed manner, without the passage of air from outside the nozzle. The aim is to form a mist of water droplets with a cross-section of less than 400 micrometers and preferably less than 90 micrometers projected axially.

[0006] Patent application US20180264486 relates to a device for single-phase spraying of liquid chemicals, including agricultural chemicals, such as pesticides or nutrients, on four sides via a nozzle structure that rotates such that the liquid chemical spraying device can be located in a flat location such as a ground surface.

[0007] Patent application WO2021 / 156125 relates to a single-phase rotary sprayer for spraying liquid through a rotating disc. The disc is designed to rotate about the axis centered on the center of the disc. The liquid applicator is designed to apply liquid to a surface of the disc. The spray guide assembly partially surrounds the disc. The inner surface of the spray guide assembly is designed to modify the trajectory of any liquids exiting the outer edge of the disc. Disadvantage of the prior art

[0008] The present invention aims to enable the spray axis, provided axial in the solution proposed by application WO2022 / 090662, to be oriented in a flexible manner to direct the two-phase jet in an appropriate direction independently of the orientation of the device, to enable the direction to be controlled when the device is fixed (mounted on the ceiling or on a wall, or on a mobile machine), or possibly held by hand.

[0009] The problem is that the generation of a two-phase jet results in a geometry without axial symmetry of the upstream part, whereas the rotating head solutions proposed by applications US20180264486 or WO2021 / 156125 concern single-phase solutions, with a single supply duct, arranged axially relative to the upstream part and relative to the inlet of the rotating head. It is not possible to adapt a rotating head known from these two prior art documents to a two-phase structure whose axial symmetry exists only at the nozzle, after mixing of the two liquid and gas phases. Solution provided by the invention

[0010] The present invention aims to enable the production of high-performance spray nozzles, particularly for firefighting, enabling the diffusion of a two-phase fog.

[0011] To this end, the invention relates to a device for generating a jet of two-phase fluid having the characteristics set out in claim 1.

[0012] It comprises a rotating nozzle, characterized in that it comprises:a fixed base having:a central connection for connecting an inlet of a first phase opening at the center of the inner surface of said fixed base,a peripheral connection for connecting an inlet of a second phase opening at the periphery, in an annular zone, of the inner surface of said fixed basea fixed body, integral with said base comprisinga central conduit for the passage of said first phase,surrounded by a coaxial annular chamber, for the passage of said second phase,a body rotating around an axis corresponding to the longitudinal axis of said fixed body, having at least one rotating joint arranged in the interface with said fixed bodysaid body having a connection for receiving a two-phase diffusion nozzle,having a longitudinal axis not aligned with the longitudinal axis with said fixed bodya central conduit for supplying the nozzle with said first phase said orifice opening on the upstream face of said body through an opening opening into said central conduitand at least one peripheral conduit, communicating with said coaxial annular chamber, for the passage of said second phase, this body comprising a means for driving in rotation relative to the fixed body.,

[0013] Preferably, said first phase is pressurized air.

[0014] Preferably, said second phase is water.

[0015] According to a first embodiment, said drive means consists of a helical shape positioned in the peripheral duct

[0016] According to a second embodiment, said drive means consists of an electric motor mechanically coupled to said rotating body.

[0017] According to a third embodiment, said drive means consists of a hydraulic motor mechanically coupled to said rotating body.

[0018] According to a fourth embodiment, said drive means consists of a magnetic ring secured to said rotating body, interacting electromagnetically with a wound peripheral stator.

[0019] According to a fifth embodiment, said drive means is a pneumatic or hydraulic motor.

[0020] According to one embodiment, said rotating body comprises at least one nozzle having a main conduit supplied with a pressurized gaseous fluid and opening into a mixing chamber, as well as at least one secondary conduit supplied with at least one pressurized liquid fluid opening into said mixing chamber in a direction forming a non-zero angle with the axis of said main conduit.

[0021] Advantageously, said mixing chamber has a convergent-divergent cylindrical wall having a constriction defining an opening in the plane perpendicular to the axis of said main conduit, the convergent part of said wall having a frustoconical zone in the extension of the axis of said at least one secondary conduit, to form a fragmentation chamber of the liquid phase.

[0022] According to one variant, the axis of said at least one secondary conduit forms with the axis of said main conduit an angle of between 2° and 20°.

[0023] According to another variant, the axes of the secondary conduits define with the generator of the cone of the converging part an angle between 0° and 60° and preferably 45% ±10°.

[0024] Advantageously, the diameter of said opening of the constriction is between 0.8 and 1.2 times the diameter of said main conduit.

[0025] According to a particular embodiment, said nozzle(s) have a mixing chamber forming a so-called Laval nozzle.

[0026] Detailed description of non-limiting examples of implementation

[0027] The present invention will be better understood upon reading the following description, referring to non-limiting examples of embodiment, illustrated by the appended drawings where:represents a front view of a first example of embodiment of a device according to the inventionrepresents a front view of a second example of embodiment of a device according to the inventionrepresents a sectional view of a device according to the inventionrepresents a longitudinal sectional view of a device according to the inventionrepresents a perspective view of a device according to the invention. General note

[0028] The description of one of these elements naturally extends to subassemblies including this element combined with another element, even if the first element is not re-described in detail in the part concerning the detailed description of this other element. Similarly, each of the elements can be used with a complementary element other than that described or even the subject of this patent: the nozzle which is the subject of the patent can be extended by a nozzle other than that proposed by this patent, just as the nozzle described can be used with nozzles other than those which are the subject of this patent. The same applies to all the elements which are the subject of a detailed description. General principle of the invention

[0029] The invention relates to a two-phase fluid generator which can be oriented angularly, in directions oblique to the longitudinal axis of an upstream base (10) constituting the supply part with a liquid and with a gas, articulated in rotation with respect to a downstream rotating body (30), on which one or more nozzles (40, 45) for diffusing the two-phase jet are mounted. The formation of the two-phase jet from a main conduit for supplying a first fluidic phase and one or more secondary conduits for supplying a second fluidic phase different from the first fluidic phase is carried out either in this downstream rotating body (30), or preferably in one or more nozzles provided with a two-phase mixer mounted on this downstream rotating body (30) transferring each of the fluidic phases via two separate conduits.

[0030] The interface between the upstream base (10) and the downstream rotating body (30) is configured to ensure fluid continuity between: the axial main conduit passing through the base (10) and the axial main conduit passing through the rotating body (30), inclined relative to the axis of the base, the secondary conduit(s) provided in the base (10) and the secondary conduit(s) provided in the rotating body (30).

[0031] For this purpose, the axial main duct passing through the rotating body (30) may have a bent shape with an axial upstream part, in the extension of the axial main duct passing through the base (10), and a downstream part oriented along the longitudinal axis of the nozzle mounted on this rotating body (30), or several downstream parts when the body comprises several nozzles.

[0032] For the secondary conduit(s), eccentric with respect to the main conduit, an advantageous solution consists of providing on the base (10) and / or on the rotating body (30) an annular groove communicating upstream with the secondary conduit(s) of the base and upstream with the secondary conduit(s) of the rotating body (30).

[0033] Description of an example of the nozzle's construction

[0034] The figure shows a front view of a first variant embodiment, with a rotating nozzle (40). The device comprises a base (10) supported by feet (11, 12) allowing fixing to a base or a ceiling.

[0035] The fixed part comprising the base (10) and the body (20) are of cylindrical geometry with a longitudinal axis (21). The rotating body (30) is extended by a nozzle (40) whose longitudinal axis (41) forms an angle of approximately 55° degrees relative to the longitudinal axis (21) of the fixed part. In the example described, it has a series of axial nozzles (31).

[0036] A rotating part arranged inside the fixed body (20) is provided with a toothed wheel (52) driven by the output pinion (51) of an electric or hydraulic or pneumatic motor. The drive could of course also be achieved by a chain or belt system.

[0037] Larepresents an alternative with two rotating nozzles (40, 45), oriented along axes (41, 42) whose rotation defines a cone coaxial with the longitudinal axis (21). Description of operation

[0038] The base (10) has two threaded holes (13, 14) intended respectively for the connection of a water supply and a pressurized air supply. The connections are shown on the front face, but one or both of them could also be provided radially.

[0039] The rotating body (30) is extended by a cylindrical rod having two coaxial conduits consisting of an annular longitudinal chamber (32) and a central conduit (34) delimited by a cylindrical partition (33). This central conduit (34) is intended for supplying the nozzle allowing the arrival of the first phase.

[0040] The annular longitudinal chamber (32) allows the circulation of the liquid phase which entered through (13) towards the annular distribution chamber.

[0041] The bore (13) for the water supply opens into an annular distribution chamber (36) formed by a flare of the annular longitudinal chamber (32). The guidance of this fixed rod (31) relative to the rotating body (30) is ensured by a rear bearing (22) and a front bearing (23). Seals (24 to 26) ensure the sealing of the circulation of the liquid phase and the gaseous phase, for example water and air.

[0042] The head of the movable part (30) has in the example described two water diffusion segments (35, 36) in an axial direction and a thread for mounting a nozzle with a central outlet (48) for supplying the fluid of the first phase, in the example described in air, and a peripheral outlet (102) for supplying pressurized air. It also comprises a peripheral duct (49) for supplying the nozzle allowing the arrival of the second phase. The annular longitudinal chamber (32) allows the liquid phase which has entered via (13) and which has been distributed by an annular distribution chamber (36).

[0043] In the example described, the driving of the rotating body (30) is carried out by a propeller (50) placed in the water flow, the passage of which creates a rotary movement. Description of an example nozzle

[0044] The description of the nozzle example illustrated by is not limiting. The invention is intended to operate with different types of two-phase diffusion nozzles.

[0045] The nozzle is crossed by a main axial channel (100), opening into the coaxial mixing chamber (105). This main channel (100) extends from an eccentric threaded connection (101) to a ring (104) opening into the mixing chamber (105).

[0046] The ring (104) ensures the transmission of the two fluids coming from the head of the rotating body to the mixing chamber (105). It comprises the main channel (100), arranged along the longitudinal axis of the intermediate body and the mixing chamber (105), and one or more secondary conduits (102, 103), typically a bundle of secondary conduits extending from the threaded connection (101) to the inlet of the mixing chamber (105). These secondary conduits (102; 103) are oriented along axes (113, 114) forming with respect to the longitudinal axis (10) an angle of approximately 10°, typically between 8 and 15°.

[0047] Other configurations may be provided, for example a conical annular chamber extending from the connector (101) to an annular outlet in the inlet of the mixing chamber (105). This conical chamber may be partitioned longitudinally to provide rigidity to the peripheral walls.

[0048] The mixing chamber (105) forms a so-called Laval nozzle. It is formed by a rectilinear conduit with variable section, consisting of a convergent part (106) extended by a divergent part (107) with a constriction (108) between these two parts (106, 107).

[0049] The converging portion (106) is configured so that an annular zone (108) is in the extension of the axes (113, 114) of the secondary conduits respectively (102, 103).

[0050] This configuration is essential for the liquid jet to break on the surface of the converging part (106) and atomize the liquid flow into a drop projected into the central vein in the jet of the gas phase and create turbulence in the converging part (107) before being drawn by the central vein through the neck (108) into the diverging part (106) of the so-called Laval nozzle.

Claims

- Device for generating a jet of two-phase fluid comprising at least one rotating nozzle, characterized in that it comprises:a fixed base (10) having:a central connector (14) for connecting an inlet of a first phase opening at the center of the inner surface of said fixed base,a peripheral connector (13) for connecting an inlet of a second phase opening at the periphery, in an annular zone, of the inner surface of said fixed base (10)a fixed body (20), integral with said base comprisinga central conduit (34) for the passage of said first phase,surrounded by a coaxial annular chamber (32), for the passage of said second phase,a body (30) rotating about an axis corresponding to the longitudinal axis of said fixed base (10), having at least one rotating joint arranged in the interface with said fixed base (10),said rotating body (30) having a connector for receiving a two-phase diffusion nozzle (40),having a longitudinal axis (41) not aligned with the longitudinal axis (21) with said fixed body (20) a central duct (48) for supplying the nozzle with said first phase opening on the upstream face of said body through an opening opening into said central duct (34) and at least one peripheral duct (49), communicating with said coaxial annular chamber, for the passage of said second phase, said body comprising a means for driving in rotation relative to said fixed body (20)., - Device for generating a jet of two-phase fluid according to claim 1 characterized in that said first phase is pressurized air. - Device for generating a jet of two-phase fluid according to claim 1 characterized in that said second phase is water. - Device for generating a jet of two-phase fluid according to claim 1 or 2, characterized in that said drive means consists of a helical shape positioned in the peripheral conduit - Device for generating a jet of two-phase fluid according to claim 1 characterized in that said drive means consists of an electric motor mechanically coupled to said rotating body. - Device for generating a jet of two-phase fluid according to claim 1 characterized in that said drive means consists of a hydraulic motor mechanically coupled to said rotating body. - Device for generating a two-phase fluid jet according to claim 1 characterized in that said drive means consists of a magnetized ring integral with said rotating body, interacting electromagnetically with a wound peripheral stator. - Device for generating a jet of two-phase fluid according to claim 1 characterized in that said drive means is a pneumatic or hydraulic motor. - Device for generating a jet of two-phase fluid according to claim 1 characterized in that said rotating body comprises at least one nozzle having a main conduit (100) supplied with a gaseous fluid under pressure and opening into a mixing chamber (105), as well as at least one secondary conduit (102, 103) supplied with at least one liquid fluid under pressure opening into said mixing chamber (105) in a direction forming a non-zero angle with the axis of said main conduit. - Device for generating a two-phase fluid jet according to the preceding claim, characterized in that said mixing chamber (105) has a convergent-divergent cylindrical wall having a constriction (108) defining an opening in the plane perpendicular to the axis of said main conduit, the convergent part (106) of said wall having a frustoconical zone in the extension of the axis of said at least one secondary conduit (102; 103), to form a fragmentation chamber of the liquid phase. - Device for generating a jet of two-phase fluid according to the preceding claim, characterized in that the axis (113, 114) of said at least one secondary conduit (102; 103) forms with the axis of said main conduit (100) an angle of between 2° and 20°. - Device for generating a jet of two-phase fluid according to the preceding claim, characterized in that the axes (113, 114) of the secondary conduits (102, 103) define with the generatrix of the cone of the converging part (106) an angle of between 0° and 60° and preferably 45° ±10°. - Device for generating a jet of two-phase fluid according to claim 10 characterized in that the diameter of said opening of the constriction (108) is between 0.8 and 1.2 times the diameter of said main conduit. - Device for generating a jet of two-phase fluid according to claim 1 characterized in that said nozzle(s) have a mixing chamber (105) forming a so-called Laval nozzle.

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